Technical Abstract:
The brown citrus aphid (BrCA), Toxoptera citricida (Kirklady), is a serious pest of citrus because it damages young growing shoots of citrus and vectors the debilitating disease, citrus tristeza virus (CTV). Integrated control strategies rely on the use of native and imported parasitoids to maintain this pest at low levels. We have selected native Lysiphlebus testaceipes (Cresson) for high levels of parasitism against BrCA, previously a poor host species for this parasitoid in nature. The laboratory-selected strain has been released in efforts to enhance natural control of the pest. The imported parasitoids, Aphelinus gossypii Timberlake and Lipolexis scutelaris Mackauer also have been released against BrCA. Monitoring the levels of parasitism caused by each of several parasitoid species attacking the same host is difficult, time consuming, and often inaccurate because the parasitoids must be reared-out in the laboratory. We developed a simple and quick molecular approach to detect and distinguish these parasitoids within single parasitized BrCA hosts.